1. Field of the Invention
The present invention relates to an ophthalmic device to measure or photograph characteristics of a subject eye, a control method for the ophthalmic device, and a program.
2. Description of the Related Art
Recently, there has been a more widespread use of intraocular lenses (IOL, also called “artificial lenses”) in eyes. Eyes that have had intraocular lenses inserted in them may be known as “IOL eyes”. Intraocular lenses have different characteristics from crystalline or natural lenses with regard to shape, material, whether or not optical power adjustment capabilities are possessed, and so forth. Accordingly, information regarding whether a subject eye is an IOL eye needs to be obtained by an ophthalmic device in order to examine an IOL eye accurately.
Japanese Patent No. 3244873 discloses a technology in which an examiner inputs whether or not the subject eye is an IOL eye into a device, and functions of a jog dial are switched depending on that input. This configuration enables the examiner to adjust, using the jog dial, the quantity of light of a fixation target for IOL eyes, which are generally more likely to contract. Since the examiner has to input whether or not the subject eye is an IOL eye, there has been the possibility that the examination may end in failure, due to misunderstanding or erroneous operations of the examiner. There has also been a problem that the input operation places an extra burden on the examiner, and that measurement time thereby takes longer.
Now, Japanese Patent Laid-Open No. 2003-290146 has disclosed a technology for an ophthalmic photography device, where the device determines whether or not a subject eye is an IOL eye from the colour of a flare, and switches the focusing method. This configuration allows precise focusing to be performed with IOL eyes which generally more readily exhibit flares.
Further, Japanese Patent Laid-Open No. 2011-136109 has disclosed a technology for an axial length measurement device where determination is made whether or not a subject eye is an IOL eye based on reflection signals from the anterior ocular segment of the subject eye, and uses an axial length calculation method that is more suitable.